Quoted in American vines (resistant stock): their adaptation, culture, grafting and propagation (1901)
By Pierre Viala, Louis Ravaz

Comptes Rendus, 21st September, 1891

Incompatibility in Grafts
Lucien Daniel

"It seems strange to see plants similarly closely related to the genus Taraxacum, such as Barkansia, Lettuce, and Chicory, behave differently; the first grafting successfully, the two other knitting well, but dying if their adventive roots are removed.

"Anatomical studies may explain this anomaly. The roots of the Taraxacum are gorged with inuline; this substance passes through the membranes of the Barkansia, which assimilates it, as may be ascertained by microscopical examination of tranverse and longitudinal sections of the graft; both stock and scion contain inuline.

"But inuline does not penetrate the scions of Lettuce or Chicory; it has never been detected in them. Therefore, they wither or die, if supplementary food is not given to them through their adventive roots. This is not an isolated case. We may understand that the membranes of some scions are impermeable to certain matters elaborated by the stock, in the same way as Lettuce and Chicory are impermeable to inuline. The failure of many grafts may thus be easily explained by a phenomenon of insufficient nutrition, without having recourse to problematic affinities between genera and species."

Daniel bibliography